Answer:
Adding ( - 7a'y + xy + 3x + 2) + (5r²y – 5cy - 6x – 7) will equal to
−7ya'+xy+5r2y−5cy−3x−5
Check the picture below.
![\bf \textit{area of a trapezoid}\\\\ A=\cfrac{h(a+b)}{2}~~ \begin{cases} h=height\\ a,b=\stackrel{bases}{parallel~sides}\\ \cline{1-1} h= x - 4\\ a = x+4\\ b=x+9\\ A=99 \end{cases}\implies 99=\cfrac{(x-4)[(x+4)+(x+9)]}{2} \\\\\\ 99=\cfrac{(x-4)[2x+13]}{2}\implies 198=\stackrel{\mathbb{FOIL}}{2x^2+5x-52}\implies 0=2x^2+5x-250](https://tex.z-dn.net/?f=%5Cbf%20%5Ctextit%7Barea%20of%20a%20trapezoid%7D%5C%5C%5C%5C%20A%3D%5Ccfrac%7Bh%28a%2Bb%29%7D%7B2%7D~~%20%5Cbegin%7Bcases%7D%20h%3Dheight%5C%5C%20a%2Cb%3D%5Cstackrel%7Bbases%7D%7Bparallel~sides%7D%5C%5C%20%5Ccline%7B1-1%7D%20h%3D%20x%20-%204%5C%5C%20a%20%3D%20x%2B4%5C%5C%20b%3Dx%2B9%5C%5C%20A%3D99%20%5Cend%7Bcases%7D%5Cimplies%2099%3D%5Ccfrac%7B%28x-4%29%5B%28x%2B4%29%2B%28x%2B9%29%5D%7D%7B2%7D%20%5C%5C%5C%5C%5C%5C%2099%3D%5Ccfrac%7B%28x-4%29%5B2x%2B13%5D%7D%7B2%7D%5Cimplies%20198%3D%5Cstackrel%7B%5Cmathbb%7BFOIL%7D%7D%7B2x%5E2%2B5x-52%7D%5Cimplies%200%3D2x%5E2%2B5x-250)
![\bf 0=(2x+25)(x-10)\implies x= \begin{cases} ~~\begin{matrix} -25 \\[-0.6em]\cline{1-1}\\[-5pt]\end{matrix}~~\\ 10 \end{cases} \\\\[-0.35em] ~\dotfill\\\\ \stackrel{\textit{larger base}}{x+9}\implies 10+9\implies 19](https://tex.z-dn.net/?f=%5Cbf%200%3D%282x%2B25%29%28x-10%29%5Cimplies%20x%3D%20%5Cbegin%7Bcases%7D%20~~%5Cbegin%7Bmatrix%7D%20-25%20%5C%5C%5B-0.6em%5D%5Ccline%7B1-1%7D%5C%5C%5B-5pt%5D%5Cend%7Bmatrix%7D~~%5C%5C%2010%20%5Cend%7Bcases%7D%20%5C%5C%5C%5C%5B-0.35em%5D%20~%5Cdotfill%5C%5C%5C%5C%20%5Cstackrel%7B%5Ctextit%7Blarger%20base%7D%7D%7Bx%2B9%7D%5Cimplies%2010%2B9%5Cimplies%2019)
keeping in mind that "x" cannot be equal to -25, since that'd give us negative values on either base and the bases are a positive value.
Answer:
but where is the relation